lamellibranch
noun
la·mel·li·branch lə-ˈme-lə-ˌbraŋk 
plural lamellibranchs
: any of a class (Lamellibranchia) of bivalve mollusks (such as clams, oysters, and mussels) that have the body bilaterally symmetrical, compressed, and enclosed within the mantle and that build up a shell whose right and left parts are connected by a hinge over the animal's back
lamellibranch adjective
Word History
Etymology
New Latin Lamellibranchia, from lamella + Latin branchia gill
First Known Use
1855, in the meaning defined above